At Apple's Yerba Buena-based special event on Tuesday, Apple notes that that days of paying for operating systems to run on your computer hardware are over.

Apple will be launching OS X Mavericks as a free upgrade for all Mac users today, Tuesday, October 22.

OS X Mavericks can be downloaded for free whether you’re on OS X Snow Leopard, OS X Lion, or OS X Mountain Lion. Apple notes that the upgrade and installation will be seamless, no matter what version of OS X you’re running. Where applicable, it will be able to be downloaded from the Mac App Store.